Aerofoil



A. E. WAGG AEROFOIL I 2 Sheets-Sheei: 1

A. E. HAGG AEROFOIL Filed April 19% 2 Sheets-Sheet 2 T 1% (I fiazy vv m x Nun/2 Patented. Sept 29, W25.

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= 3,, ""l GG, @lfi MEZDDLESEX, ENGLAND, ASSIGNUR TO THE DE HAVILLAND I? CGMPAWY, YLIMITED, 01E EDGEWARE, MIDDLESEX, ENGLAND.

AEEGEGIL.

Application filed April 1, 1924:. Serial'lto. Wi -79.

To all whom it may concern: 7

Be it known that l, ARTHUR ERNEST HAGG,

subject of the King of England, residing in c v suited for horizontal flight. In one known and frequently adopted means for varying the efiective cambering of an aeroplane wing a rear or trailing edge-portion of the aerofoil is so mounted that it can be deflected upwardly or downwardly with respect to the main wing portion.

An object of the invention is to provide means automatically controlling the cambering to suitthe particular speed of the aerofoil without giving the pilot an additional control to attend to, and also to allow him still to have means by which he can vary the cambering at will for other purposes necessary or requisite for the eflicient control of the machine of which the aerofoil in question constitutes a part.

The type of control'mechanism to which i the present invention is applied, comprises in combination automatice lly operating yielding control means of such a character as to control automatically the movement of said flexible or movable part so as to permit it to assume automatically in flight a posi tion or a degree of camber best suited to the air-speed of the aerofoil. a movable intermediate member constituting part of an operative connection between the yielding control means and the flexible or movable'part, and a memberwhich is carried on or is adjustable relatively to the said intermediate member, which is onerativcly connected to the flexible or movable part and which constitutes part of a manually operable means by which the pilot can impart any desired adjustment to the flexible or movable art irrespective of or additional to the ad1ustment automatically allowed by or imposed by the said yielding means.

According to the present invention control mechanismof the type above described 1s applied or is to be applied to an aerofoil having at least two separately flexible or movable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil and is characterized by at least two inter mediate movable members allocated one to each of said flexible or movable parts and also by means coupling the said intermedi ate members together wherebythey are movable in company and in such a manner that movements imparted by or through them to their respective aerofoil parts on both sides of the said centre line are substantially equal in degree and are in the same direction.

According to a further feature of the invention the control mechanism is characterized by other members which are carried on each of the said intermediate: members and constitute part of the manually operable control means above referred to, and by means coupling the said other members together and to a single manual control device in such a manner that movements imparted by or through said other members to the movable or flexible aerofoil portions on one side of the fore and aft centre line are opposite in direction to those imparted to similar aerofoil portions on the opposite side of that centre line.

In the referred construction the flexible or otherwise movable part will be a flap or trailing edge part. .7 a

Where the term movable, as applied to the movable or flexible aerofoil portions, is used hereinafter and in the claims, it is intended to cover, and it is to be understood as including, not only bodily movement, but movement of that part by flexing. Moreover, the termautomatically operating yielding control means is to be understood as referring to any yielding means which automatically permits the mew able aerofoil parts to assume a position best suited to the air-speed of the aerofoil, such means being, if necessary, capable of initial adjustment or of readjustment from time to time but requiring no manual control during flight.

The foregoing and other features of the invention will be more readily appreciated from the following description of one preferred construction according to the invention given-by way of example only, with the aid of the accompanying drawings, in which Figure 1 shows diagrammatically in plan parts of an aeroplane showing the arrangement of the control devices according to the invention;

Figure 2 is an end view on an enlarged scale and partly diagrammatic of the construction shown in Figure 1, looking from the left; and

Figure 3 is a plan of the parts shown in Figure 2, without the material of the wing covering.

Like reference numerals indicate like parts in the several figures of the drawings.

To the trailing edges of the main planes on each side of the aero lane-body 10 are hinged ailerons 11. As s own more clearly in Figures 2 and 3 each aileron 11 is hinged at 12 to the rear spar 13 of the main plane, the front spar of which is indicated at 14.

Situated within the thickness of the plane on each side of the machine is a mechanism, similar in both cases but opposite handed, illustrated in detail in Figures 2 and 3, the one therein shown being for the left or port side. In this mechanism, in a bracket 15 there is fulcrumed at 16 a swinging arm 17 having extensions 18 both fore and aft of the fulcrum.

The extensions 18 are connected by cables 19 to the similar or duplicate mechanism on the other side of the machine as shown in Figure 1, these cables being crossed. An elastic member 20, one'for each of the arms 17, is connected at one end to the forward extension 18 and at the other end to a fixed portion of the structure of the machine at 21. The elastic member may be conveniently of rubber cord held in tension and is so arranged in magnitude and direction as to balance the forces imparted to the swinging arm 17 by air pressure underneath the trailing portion of the aerofoil as will be more clearly understood hereinafter.

In the arm 17 is journalled a spindle 22 at the upper end of which is carried a sprocket 23. This is connected by means of a flexible connector 21 with a similar sprocket on the duplicate mechanism on the opposite side of the machine, chain portions being provided in the connector 24- to engage the sprockets. In one lap of the connector 21 is connected at (Figure 1.) control mechanism operable at will by the pilot. for example by means of the control stick 26. At the lower end of the spindle 22 there is rigidly secured an arm 27 and this is pivotally connected to one end of a rigid tie The other end of the latter is pivotally con nected to an arm 29 extending downwardly from the underside of the aileron 11. The construction and arrangement of the con nector 24, spindles 22, sprockets 23, lever connections 27, 28 and 29, together with the operating mechanism diagrammatically represented at 25, 26 may all be similar to the corresponding parts described in our prior British Patent No. 184,317. This arrangement ensures that the aileron which is being upwardly moved is displaced through a greater angle than is that which is being downwardly moved for reasons which are well understood.

It will now be seen, therefore, that while the pilot can manually control the ailerons 11 through the medium of the connector 2i and its associated parts when he desires so to do, the ailerons will otherwise automatically assume a position in flight best suited to the air speed of the machine by reason of the fact that the arms 17 are movable bodily about their fulerums 16 (together with the pilot-controlled portions of the mechanism carried on them) against the tension of the members 20. Owing to the crossed cables 19 any movement of the swinging arm 17 on one side of the machine will be accompanied by an equal and similar movement of its counterpart on the other side of the machine. Normally therefore, the effective camber of the aerofoil constituting the main fixed portions of the plane and the ailerons will become automatically adjusted according to the air speed of the machine, while lateral control is obtained at will by imparting movement to the ailerons in different directions at the will of the pilot.

Means, for example a tension adjusting device, may be provided for adjusting the strength of the spring or other resilient device when it is desired to do so.

It is obvious that although one particular construction has been described in detail for carrying the invention into effect many modifications may be made in the form, construction and arrangement of the parts employed without departing from the spirit of the invention.

\Vhat I claim as my invention and desire to secure by Letters Patent is 1. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil. the combination of automatically operating yielding control means for said parts, intermediate members operatively connecting said yielding control means with the movable parts and allocated one to each of said parts, means coupling said intermediate members together whereby they are movable in company in such manner that movements imparted through them to their respective aerofoil parts are substantially equal in degree and in the same direction, and manually operable control means for said movable parts.

2. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of automatically operating yielding control means for said parts, intermediate members operatively connecting said yielding control means with the movable parts and allocated one to each of said parts, means coupling said intermediate members together whereby they are movable in company in such manner that movements imparted through them to their respective aerofoil parts are substantially equal in degree and in the same direction, and manu ally operable control means for said movable parts such that movement imparted through said means to a movable aerofoil part on one side of the said centre line is opposite in direction to that impartedto a similar part on the other side of that line.

3. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of automatically operating yielding control means for said parts, intermediate members operatively connecting said yielding control means with the movable parts and allocated one to each of said parts, means coupling said intermediate members together whereby they are movable in company in such manner that movements imparted through them to: their respective aerofoil parts are substantially equal in degree and in the same direction, and manu ally operable control means for said movable parts such that movement imparted through said means to a movable part, on one side of said centre line is opposite to that imparted to a similar part on the other side of that centre line and is different in degree. v i p 4. For an aerofoil having at least two separately. movable and adjustable parts dis posed respectively on opposite sidesof the fore and aft centre line of the aerofoil, the combination of automatically operating yielding control means for said parts, intermediate" members operatively connecting said yielding control means with the movable parts and allocated one to each of said parts, means coupling said intermediate members together whereby they are movable in company in such manner that movements imparted through them to their respective aerofoil parts are substantially equal in degree and in the same direction, manually operable control means for said movable parts, said manually operable means comprising an element adjustably mounted in each intermediate member, and coupling means whereby movement imparted through the manually operable means to a movable aerofoil part on one side of the said centre line isopposite in direction to that imparted to a similar part on the other side of that line.

5. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of automatically operating yielding control means for said parts, intermediate members operatively connecting said yielding control means with the movable parts and allocated one to each of said parts, means coupling said intermediate members together whereby they are movable in company in such manner that movements imparted through them to their respective aerofoil parts-are substantially equal in degree and in the same direction, manually operable control means for said movable parts,

said manually operable means comprising line.

6. For an aerofoil having atleast two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of automatically operating yielding control means for said parts, intermediate members operatively connecting said yielding control means with the movable parts and allocated one to each of said parts, means coupling said intermediate members together whereby they are movable in company in such manner that movements imparted through them to their respective aerofoil parts are substantially equal in degree and in the same direction, and manually operable control means comprising elements operatively connected one with each of said aerofoil parts, each such element and its appropriate intermediate member being pivoted about different axes spaced apart and transverse to the general plane of the aerofoil.

7 For ,an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of automatically operating yielding control means for said parts, intermediate members operatively connecting said yielding control. means with the movable parts and allocated one to each of said movable parts,.means coupling said intermediate members together whereby the are movable in company in such manner that movements imparted through them to their respective aerofoil parts are substantially equal in degree and in the same direction, and manually operable control means comprising elements operatively connected one with each of said aerofoil parts, each such element and its appropriate intermediate member being pivoted about different axes spaced apart and transverse to the general plane of the aerofoil, said elements being so coupled that movement imparted through them to the aerofoil parts on opposite sides of the said centre line are in opposite directions.

8. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of automatically operating yielding control means for said parts, intermediate members operatively connect ing said yielding control means with the movable parts and allocated one to each of said parts, means coupling said intermediate members together whereby they are movable in company in such manner that movements imparted through them to their respective aerofoil parts are substantially equal in degree and in the same direction, and manually operable control means comrisin elements 0 erativel connected onewith each of said aerofoil parts, each such element and its appropriate intermediate members being pivoted about diilerent axes spaced apart and transverse to the general p ane of the aerofoil, each said element also constituting an operative connection between the intermediate member and its appropriate aerofoil part.

For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil,

the combination of automatically operating yielding control means for said parts, intermediate members operatively connecting said control means with the movable parts and allocated one to each of said parts, means coupling said intermediate members together whereby they are movable in company in such manner that movements imparted through them to their respective aerofoil parts are substantially equal in degree and in the same direction, and manually operable control means comprising spindles operatively connected one with each of said aerofoil parts, each such spindle and its appropriate intermediate member being pivoted about different axes spaced apart and transverse to the general plane of the aerofoil, each said spindle constituting a portion of an operative connection between the intermediate member and the appropriate 'aerofoil part.

p? 10. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of two pivoted brackets allocated one to each of said aerofoil parts, and in each bracket a pivoted crank the pivotal axis of which is offset from that of the bracket, means connecting said crank with its appropriate aeroioil part, yielding control means connected with each said bracket, and manually operable control means for rotating said crank at will.

11. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of two pivoted brackets allocated one to each end of said aerofoil parts, and in each bracket a pivoted crank the pivotal axis of which is oflset from that of the bracket, means connecting said crank with its appropriate aerofoil part, yielding control means connected with each said bracket, and manually operable control. means for rotating said cranks at will, said means coupling both cranks in such a manner that movements imparted through them to their respective aerofoil parts will be in opposite directions.

12. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of two pivoted brackets allocated one to each of said aerofoil parts, and in each bracket a pivoted crank the pivotal axis of which is offset from that of the bracket, means connecting said crank with its appropriate aerofoil part, yielding control means connected to each bracket on the same sides of their pivotal axes, and manually operable control means for rotating said cranks at will, said means coupling both cranks in such manner that movements imparted through them to their respective aerofoil parts will be in opposite directions.

13. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of two pivoted brackets allocated one to each of said aerofoil parts, two connectors extending respectively from points on opposite sides of the pivotal axis of one bracket to points on opposite sides of the pivotal axis of the otherbracket, said connectors being crossed for the purpose described, resilient control means for each bracket, a crank pivotally mounted in each bracket with its pivotal axis ofiset from the pivotal axis of its bracket, an endless bandlike connector coupling both said cranks so that movements imparted simultaneously to them by said endless connector are in the same direction, means coupling each crank with its respective aerofoil part, and a manually operable member for imparting movement to the said band-like coupling member.

14:. For an aerofoil having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of two pivoted brackets allocated one to each of said aerofoil parts, two connectors extending respectively from points on opposite sides of the pivotal axis of one bracket to points on opposite sides of the pivotal axis of the other bracket, said connectors being crossed for the purpose described, resilient control means for each bracket, a crank pivotally mounted in each bracket with its pivotal axis oifset from the pivotal axis of its bracket, a sprocket mounted to rotate with each crank, an endless chain passing round both said sprockets so that movements imparted simultaneously through them to the aerofoil parts by means of the chain are in opposite directions, means coupling each crank with its respective aerofoil part, and a manually operable member for imparting movement to the said chain.

15. For an aerofoil' having at least two separately movable and adjustable parts disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of two pivoted brackets allocated one to each of said aerofoil parts, two connectors extending respectively from points on opposite sides of the pivotal axis of one bracket to points on opposite sides of the pivotal axis of the other bracket, said connectors being crossed for the purpose described, resilient control means 'for each bracket, a crank pivotally mounted in each bracket with its pivotal axis ofi'set from the pivotal axis of its bracket, a sprocket mounted to rotate with each crank, an endless chain passing round both said sprockets so that movements imparted simultaneously through them to the aerofoil parts by means of the chain are in opposite directions, means coupling each crank with its respective aerofoil part, and a swinging lever for imparting manually controlled movement to said chain.

16. For an aerofoil having at least two separately movable and adjustable flaps disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of two brackets pivotally mounted bn the structure'of the aerofoil and allocated one to each of said flaps, two connectors extending respectively from points on opposite sides of the pivotal axis of one bracket to points on opposite sides of the pivotal axis of the other bracket, said connectors being crossed for the purpose described, resilient control means for each bracket, a crank pivotally mounted in each bracket with its pivotal axis offset from the pivotal axis of its bracket, an arm depending from each flap, a rod connecting each crank with the arm extending from its appropriate flap, and an endless bandlike connector coupling both said cranks so that mo.ements imparted through them simultaneously by said endless connector are in opposite directions.

17. For an aerofoil having at least two separately movable and adjustable flaps disposed respectively on opposite sides of the fore and aft centre line of the aerofoil, the combination of two brackets pivotally mounted on the structure of the aerofoil and allocated one to each of said flaps, two connectors extending respectively from points on opposite sides of the pivotal axis of one bracket to points onthe opposite sides of the pivotal axis of the other bracket, said connectors being crossed for the purpose described, resilient control means for each bracket, a crank pivotally mounted in each bracket with its pivotal axis ofi'set from the pivotal axis of its bracket, an arm depending from each flap, a rod connecting each crank with the arm extending from its appropriate flap, a sprocket rotatable with each crank, and an endless chain coupling both said sprockets so that movements imparted simultaneously through them to the flaps by movement of said chain are in opposite directions.

, 18. The combination of an aerofoil a part of which is movable relatively to the remainder thereof for the purpose of varying its effective angle of incidence, yielding means to control automatically the movement of said part, said yielding means being such that it will permit said part to assume automatically in flight a position which is best suited to the air-speed of the aerofoil, a swinging member which constitutes part of a connection between the said movable part and the yielding means for controlling it, and manually controllable means mounted on said member for adjusting at will said movable part.

19. The combination of an aerofoil, a trailing edge part of which is movable relatively to the other portion of the aerofoil for the purpose of varying its efiective angle of of which is movable relatively to the remainder thereof for the purpose of varying its effective angle of incidence, yielding means to control automatically the movement of said part, said yielding means being such that it will permit said part to assume automatically in flight a position which is best suited to the air-speed of the aerofoil, a swinging member which is pivoted about an axis transverse to the general plane of the aerofoil and which constitutes part of a connection between the said movable part and the yielding means for controlling it, and a manually controllable means for adjusting at will the move ment of said part, said manually control- .lable means comprising a spindle which is also transverse to the general plane of the aerofoil and is itself operatively connected with the said movable part of the aerofoil whereby the spindle and the means operatively connecting it with the said movable part constitute an operative connection between the swinging member and said part.

21. The combination of an aerofoil, a trailing edge part of which is movable relatively to the other portion of the aerofoil for the purpose of varying its effective angle of incidence, yielding means to control automatically the movement of said trailing edge part, said yielding means being such that it will permit said edge part to assume auto matically in flight a position which is best suited to the air-speed of the aerofoil, a swinging member which is pivoted about an axis transverse to the general plane of the aerofoil and which constitutes a part of a connection between the said trailing edge part and the yielding means for controlling it, and a manually controllable means for adjusting at will the movement of said part, said manually controllable means comprising a spindle which is also transverse to the general plane of the aerofoil and is itself operatively connected with the said trailing edge part of the aerofoil whereby the spindle and the means operatively connecting it with the said trailing edge part constitute an operative connection between the swinging member and said part. r

22. The combination of an aerofoil the trailing edge part of which, on each side of the fore and aft centre line, is movable relatively to the other portion of the aero foil for the purpose of varying its effective angle of incidence, a swinging member for each trailing edge part, said swinging member being pivoted about an axis which is transverse to the general plane of the aerofoil, the said pivotal axis being fixed in relation to the main body of the aerofoil, yielding means connected with each of said swinging members to control the move mentthereof, connectors between said two swinging members so that their movements are synchronized, and a lever connecting each said member with its respective edge art. i

p 23. The combination of an aerofoil the trailing edge part of which, on each side of the fore and aftcentre line, is movable relatively to the other portion of the aerofoil for the purpose of varying its effective angle of incidence, a swinging member for each trailing edge part, said swinging member being pivoted about an axis which is transverse to the general plane of the aerofoil, the said pivotal axis being fixed in relation to the main body of the aerofoil, yielding means connected with each of said swinging members to control the movement thereof, connectors between said two swinging members so that their movements are synchronized, a crank pivoted in each of said swinging frames eccentrically with but about an axis parallel to the pivotal axis of-said frame, a lever connecting each said crank with its respective edge part, a connector between said two cranks, and manually operable means combined with said connector, substantially as described.

In testimony whereof I affix my signature.

ARTHUR ERNEST HAGG. 

